Electrode for electric arc welding or soldering



?atented Jan. 3, 1933 EDWARD JOHN CLARKE, OF GHARIN G CROSS, ENGLAND, ASSIGNOR, BY MESNE ASSIGN- MENTS, TO AMERICAN MUREX CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE ELECTRODE FOR ELECTRIC ARC WELDING OR SOLDERING No Drawing. Application filed October 28, 1929, Serial No. 403,134, and in Great Britain March 18, 1929.

This invention relates to metallic electrodes for use in electric arc welding or soldering of the kind in which the electrode comprises a core of mild or alloy steel and a coating containing fluxing materials and metals, the latter being such that when fus on of the electrode takes place under the action oi the electric are there are obtained and deposited upon the work by the arc alloy steels which are heat-resistant at relatively high temperatures and/0r resistant to oxidizing or other corrosive effects occasioned by the action of moisture, acids or alkalis.

Previously electrodes for the deposition of stainless steel have comprised a mild steel core wound with asbestos yarn or other suit able non-conducting composition or material in open spirals together with an extruded coating composed of the usual fluxing ingredients and a certain proportion of powdered ferro-chromium or chromium metal; when fusion takes place under the action of the electric arc the chromium or ferro-chromium alloys with the mild steel and a deposit of stainless steel results. Electrodes for depositing stainless steels containing nickel, chromium and iron have also been made by electrolytically depositing the nickel upon a mild steel core, winding the rod so prepared with asbestos and then coating it with a compound containing powdered metallic chromium in addition to the usual fluxing ingredients. -There is a limit however to the amount of metals which may be added to the coating of such electrodes. In those cases where the amount of added metals is relatively high, complete solution of the iron, nickel and chromium does not take place.

The present invention has for its object to overcome difficulties of the kind just mentioned where alloy steels containing as essential ingredients nickel and chromium with or without tungsten or molybdenum are to be deposited by the electrode, and for this purpose according to the invention the core of the electrode, consisting of a mild or alloy steel, is provided with a coating containing, in addition to the usual fluxing materials and/or slag-forming materials, an alloy (in the powdered state) of nickel and chromium with or without tungsten or molybdenum in the proportions required to be alloyed with the metal of the core for the roduction of the alloy steel finally desired. buitable alloys for this purpose are by way of example as follows :20 parts nickel, 10 parts molybdenum and 70 parts chromium, 25 parts nickel and 75 parts chromium.

In cases where the amount of added metal that it is desired to alloy with the metal of the electrode core is greater than that which it would be possible to include in the coating of the electrode, the core rod itself is formed of an alloy steel wire containing a proportion of the non-ferrous metals ultimately required in the finished weld, the greater part of the additional non-ferrous metals however being incorporated in the form of an alloy with the electrode coating. For example the core rod may comprise an alloy steel containing about 5 to 20 per cent of chromium and up to 10 per cent of nickel, whilst a proportion of chromiuin amounting to about three to four times as much as the lower percentage just mentioned would be contained in the electrode coating in the form of a nickel chromium alloy.

In order that the said invention may be clearly understood and readily carried into effect, there will now be described an example of the manufacture of an electrode for depositing an austenitic stainless steel. The core of the electrode, consisting of the usual mild steel, may first be given a coating of nickel or not as desired, and is then wound with asbestos yarn in open spirals. As a suitable coating composition there may be taken one consisting of 1 part of a flux comprising equal parts of fluorspar and calcium carbonate and 2 parts of a powdered nickel chromium alloy comprising 1 part of nickel and 3 parts chromium; this coating composition is then made into a paste with a suitable agglutinant such as sodium silicate solution and the paste is extruded upon the rod between the open spirals.

WVith the improved electrodes according to the present invention the metal deposits obtained under the action of the electric are have been found to be extremely satisfactory and to be free from the disadvantages resulting from the employment of electrodes made by the methods heretofore in use.

What I claim and desire to secure by Letters Patent of the United States is 2-- 1. In an electrode for electric arc-welding and soldering wherein a stainless steel weld is produced, a core for the electrode consisting of a mild alloy steel provided with a coating of fluxing and slag-forming materials, the coating of the electrode containing an alloy, in the powdered state, of nickel and chromium in proportions adapted to be alloyed with the metal of the core for the production of a stainless alloy steel. i

2. In an electrode according to claim 1, a coating for the electrode containin dered alloy of nickel, chromium, an molybdenum.

3. In an electrode according to claim 1, a coating for the electrode containing a powdered alloy of nickel, chromium, and tungsten.

4. In an electrode for electric arc-welding and soldering, a core rod comprising an alloysteel containing about 5 to 20 per cent of chromium and up to 10 per cent'of nickel, about three to four times the lower percentage of chromium being contained in the electrode foating in the .form of a nickel-chromium alt). In an electrode for electric arc-welding and soldering, a mild steel core wrapped with asbestos yarn in open spirals and having a coating composition between said spirals comprising a flux and a nickel-chromium alloy, said alloy consisting of nickel and chromium in about the proportions by weight of 1 to 3.

6. In an electrode for electric arc-welding and soldering, a mild steel core coated with a compostion containing a powdered allo of nickel, molybdenum and chromium in a out the proportions by weight of 20: 10:70, respectively.

7. In an electrode for electric arc-welding and soldering, a mild steel core coated with a composition containing a powdered alloy of nickel and chromium in about the proportions by weight of 25 75, respectively.

8. In an electrode for electric arc-welding and soldering wherein a stainless steel weld of predetermined composition is produced, a core consisting of an alloy steel containing a minor proportion of the nickel and chromium required in said weld and coated with a composition containing the major proportion of the nickel and chromium required in said weld; the nickel and chromium contained in said coating being in the form of a powdered nickel-chromium alloy.

EDWARD JOHN CLARKE.

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